<template>
  <div>
    <h1>Son {{ count }}</h1>
    <button @click="$emit('input', count++)">点击</button>
  </div>
</template>

<script>
export default {
  name: 'Son',
  data() {
    return {
      count: 0,
    }
  },
  props: ['value'],
  mounted() {
    this.count = this.value
  },
}
</script>

<style></style>
